Fatality risk isn't the same in all vehicles, driver death rates show

Car, minivan, SUV, and pickup truck models vary widely in the likelihood of dying in a crash. The average driver death rate in 1999-2002 passenger vehicle models during 2000-03 was 87 per million registered vehicle years. But the death rates in some models were two or even three times as high, while the rates in other vehicles were much lower.

Large cars and minivans dominate among vehicle models with very low death rates. The models with the highest rates are mostly small cars and small and midsize SUVs, many of which also have high rates of death in single-vehicle rollover crashes. The model with the highest death rate of all — the two-door, two-wheel-drive Chevrolet Blazer with 308 driver deaths per million registered years — also had the highest rollover death rate (251 per million).

"Many of these general patterns of death rates have been consistent since the Institute began computing the rates by vehicle make and model in the late 1980s," says Institute chief operating officer Adrian Lund (see Status Report special issue: occupant death rates, Nov. 25, 1989). "Since then there also has been a pattern of improvement. In the late 1980s the overall driver death rate was higher than 100. The latest overall rate was 87."

Vehicle body style, size, and fatality risk

Important characteristics of vehicles that influence their driver death rates are type, body style, size, and weight. Within virtually every group of vehicles, the smaller and lighter models have the higher rates.

Among cars, for example, the smallest two-door models had the highest death rate at 190 per million vehicle years. This rate is more than twice as high as the average for all vehicles included in the study.

Midsize sports cars also had a high rate at 133 driver deaths per million vehicle years. This was higher than for either small or mini sports cars, so this type of vehicle was an exception to the general rule that bigger means lower death rates.

The vehicle group with the lowest driver death rate was large luxury cars with 37 deaths per million vehicle years. The next lowest rate was in large minivans and station wagons with 42 deaths per million.

Body style and size

Driver death rates by size and body style group, per million registered vehicle years

OVERALL

Multiple- vehicle crashes

Single- vehicle crashes

Single- vehicle rollovers

CARS

4-DOOR

mini

148

94

53

26

small

110

65

43

22

midsize

76

43

32

15

large

79

48

29

12

very large

71

43

30

12

2-DOOR

mini

190

116

75

40

small

130

62

67

39

midsize

94

42

52

30

large

75

37

38

19

SPORTS

mini

86

46

38

19

small

61

25

35

14

midsize

133

48

85

42

LUXURY

midsize

41

20

20

11

large

37

19

19

7

very large

47

26

20

7

SPECIALTY

small

115

60

54

28

MINIVANS AND STATION WAGONS

small

65

49

15

2

midsize

47

11

40

27

large

42

26

15

9

SUVs

4-WHEEL DRIVE

small

102

39

65

51

midsize

67

22

48

34

large

52

14

40

31

very large

103

19

92

75

2-WHEEL DRIVE

small

121

60

61

43

midsize

114

38

80

63

large

70

31

39

31

PICKUPS

4-WHEEL DRIVE

small

109

32

77

53

large

97

29

69

49

very large

95

27

68

51

2-WHEEL DRIVE

small

124

56

68

39

large

107

38

70

42

very large

69

31

38

22

SPECIALTY

midsize

93

34

64

62

Vehicle weight and the risk of death

Because vehicle size and weight are so closely related, it shouldn't be surprising that their effects on driver death rates are similar. In each group (cars, SUVs, pickups) the heavier vehicles, like bigger ones, generally had lower death rates. The rate in the lightest SUVs, for example, was more than twice as high as in the heaviest SUVs.

"Pound for pound across the vehicle types, cars almost always have lower death rates than either pickups or SUVs. This generally is because the SUVs and pickups have much higher rates of death in single-vehicle rollover crashes," Lund explains.

In some weight groups, the death rates in cars were dramatically lower. For example, the rate in cars weighing 3,501 to 4,000 pounds was about half of the rates in pickups or SUVs of similar weight. The exception was light pickups, which had relatively low rates compared with cars or SUVs weighing about the same.

"There's no ready explanation for this exception," Lund says. "It probably has something to do with how light pickups are driven and their use patterns compared with larger and heavier pickups."

Influence of vehicle weight

Driver deaths per million registered vehicle years, 1999-2002 models during 2000-03

CARS

SUVs

PICKUP TRUCKS

Vehicle weight

OVERALL

Multiple-vehicle crashes

Single-vehicle crashes

Single-vehicle rollovers

OVERALL

Multiple-vehicle crashes

Single-vehicle crashes

Single-vehicle rollovers

OVERALL

Multiple-vehicle crashes

Single-vehicle crashes

Single-vehicle rollovers

≤ 2,500 lbs

115

71

42

20

—

—

—

—

—

—

—

—

2,501-3,000 lbs.

102

54

46

25

128

63

66

47

90

42

49

28

3,001-3,500 lbs.

84

44

39

19

98

38

61

47

131

57

74

45

3,501-4,000 lbs.

56

33

23

10

98

32

69

53

115

33

82

56

4,001-4,500 lbs.

47

27

20

7

73

23

53

39

107

38

70

44

4,501-5,000 lbs.

—

—

—

—

66

27

40

28

93

30

64

41

> 5,000 lbs.

—

—

—

—

55

15

42

33

87

28

60

44

— no exposure or insufficient exposure

Rates differ among similar vehicles

Besides these broad death rate differences across vehicle groups, the rates varied within body style and size groups. In almost every size group of two-door and four-door cars, for example, the death rate for the worst vehicle was at least twice as high as the rate for the best vehicle.

Consider the Infiniti G20's rate of 46 deaths per million registered years, which was much lower than rates for other small four-door cars. The Chevrolet Cavalier's rate was 162 per million, and the Pontiac Sunfire's was 160. The upper confidence bound for the G20's death rate is well below the lower confidence bounds for the other two cars.

"This means that the lower death rate for the G20 wasn't due to chance," Lund says. A more extreme example involves midsize four-wheel-drive SUVs. The Toyota 4Runner had only 12 driver deaths per million registered years during 2000-03. This compares with 134 deaths per million for the two-door Ford Explorer and 119 per million for the Land Rover Discovery Series II.

Single-vehicle versus multiple-vehicle crashes

In many vehicle groups, driver death rates are split fairly evenly between single- and multiple-vehicle crashes. But there are exceptions. Most driver deaths in large four-door cars and minivans occurred in crashes involving other vehicles. In contrast, in pickup trucks and SUVs of almost every size more deaths occurred in single-vehicle crashes. In large four-wheel-drive SUVs, for example, the death rate was almost three times as high in single-vehicle crashes as it was in collisions involving two or more vehicles (14 deaths per million compared with 40).

Rollover crashes

Eleven vehicles, all pickups or SUVs, had more than 75 driver deaths per million in single-vehicle rollover crashes. This is in large part because pickup trucks and SUVs have relatively high centers of gravity compared with cars. The Ford Excursion is a very large SUV with a high rollover death rate. This is at least in part because its occupancy rate tends to be high, which raises its center of gravity even higher.

The vehicle with the very highest driver death rate in single-vehicle rollover crashes was the two-door, two-wheel-drive Chevrolet Blazer. The 251 deaths per million for this SUV compare with an average of 63 for all midsize two-wheel-drive SUVs, 34 for four-wheel-drive versions, and 28 for all vehicles in the study.

Not all midsize SUVs had high death rates in single-vehicle rollovers. The Lexus RX 300, Toyota 4Runner, Nissan Pathfinder, and Acura MDX had 6 or fewer rollover deaths per million vehicle years. Both the RX 300 and the 4Runner are equipped with electronic stability control, which has been shown to significantly reduce the risk of fatal single-vehicle crashes, including rollovers (see "Electronic stability control reduces deaths, especially in single-vehicle crashes," Jan. 3, 2005).

Not one driver death occurred in a rollover of the RX 300 or four-wheel-drive Toyota RAV4, a small SUV. This experience doesn't mean the rates for these vehicles will be zero every year, but it does mean very low rates can be expected.

"Small SUVs have had high rollover death rates in previous years, but as the RAV4 indicates this may be changing. One reason may be that the drivers are changing," Lund points out. "It used to be that younger people, especially young men, drove small SUVs, but now many women drive them, including older women. In addition, as vehicle manufacturers redesign their small SUVs they're addressing the rollover problem in the designs, making these vehicles more stable and less likely to roll over."

How the death rates were computed

Rates of driver death in all crashes plus rates in multiple-vehicle, single-vehicle, and single-vehicle rollover crashes were computed for 199 passenger vehicle models (1999-2002) with at least 120,000 registered vehicle years or 20 driver deaths during the study years.

Each model's rate represents the reported number of driver deaths divided by the model's number of registered years. Data are from the federal government's Fatality Analysis Reporting System and registration counts from The Polk Company.

Among the vehicles, exposure varies considerably. For example, the number of registered vehicle years for midsize two-door cars is nearly 3 million. This compares with fewer than 300,000 registered years for large two-door cars. Because of this variability, 95 percent confidence intervals were computed with upper and lower bounds indicating the precision of the computed rates for all crash types.

The rates reflect primarily the influence of a vehicle's design and patterns of use. Because driver demographics can be a major influence, the death rate for each vehicle was adjusted according to the proportion of deaths of women 25-64 years old. These drivers are involved in fewer fatal crashes per licensed driver. For most vehicles the rates were adjusted by less than 20 percent.

"This is the first year we've adjusted the rates to account for some driver characteristics," Lund says. "The adjustment takes away some of the differences among vehicles caused by differences in driver gender. Other demographic factors still influence the death rates, but more of the differences in the rates reflect the vehicles."

Lowest rates of driver deaths

Fewer than 30 driver deaths per million registered years, 1999-2002 models during calendar years 2000-03

OVERALL

Multiple-vehicle crashes

Single-vehicle crashes

Single-vehicle rollovers

Mercedes E-Class

luxury car

large

10

7

3

0

Toyota 4Runner

4WD SUV

midsize

12

6

6

6

Volkswagen Passat

4-door car

midsize

16

0

18

13

Lexus RX 300

4WD SUV

midsize

17

11

5

0

Toyota RAV4

4WD SUV

small

18

12

6

0

Honda Odyssey

minivan

large

19

16

2

1

Mercury Villager

minivan

large

21

7

15

7

Mercedes S-Class

luxury car

very large

25

15

10

0

Nissan Pathfinder

4WD SUV

midsize

25

8

17

4

Cadillac DeVille

luxury car

large

26

12

14

4

Nissan Quest

minivan

large

26

23

0

0

Toyota Camry Solara

2-door car

midsize

27

10

16

11

Cadillac Eldorado

luxury car

large

29

12

17

6

2WD: 2-wheel drive; 4WD: 4-wheel drive

Highest rates of driver deaths

More than 160 driver deaths per million registered years, 1999-2002 models during calendar years 2000-03

OVERALL

Multiple-vehicle crashes

Single-vehicle crashes

Single-vehicle rollovers

Chevrolet Blazer 2dr

2WD SUV

midsize

308

54

274

251

Mitsubishi Mirage

2-door car

small

209

142

69

37

Pontiac Firebird

sports car

midsize

205

42

167

71

Kia Rio

4-door car

mini

200

95

109

64

Kia Sportage 4dr

2WD SUV

small

197

65

138

88

Chevrolet Blazer 4dr

2WD SUV

midsize

190

78

113

79

Ford Explorer 2dr

2WD SUV

midsize

187

52

145

122

Chevrolet Camaro

sports car

midsize

186

62

123

63

Mazda B series

2WD pickup

small

185

67

124

88

Chevrolet Tracker

4WD SUV

small

183

86

98

80

Chevrolet S10

2WD pickup

small

182

81

101

61

Chevrolet Cavalier

2-door car

small

168

90

76

49

Chevrolet Cavalier

4-door car

small

162

83

81

44

Kia Sportage 4dr

4WD SUV

small

162

51

119

100

2WD: 2-wheel drive; 4WD: 4-wheel drive

Sources of data are the National Highway Traffic Safety Administration's Fatality Analysis Reporting System and The Polk Company's National Vehicle Population Profile.